23/10/2017

1

NMR-MICP Integration& PermeabilityEstimation: A New FreePetrophysics SoftwareP.V. Mesquita, R. B. V. Azeredo, E. H. Rios, A. Souza, B. A. C. Silva, B. M. Faria, A. Boyd

• Background Theory

• Motivation & Goals

• Main software features

• Conclusions and considerations for the future

Outline

23/10/2017

2

(1) http://accutech.metadot.com/index.pl?r=1 (2) www.spe.org/jpt/article/10327-technology-update-24

NMR in Formation Evaluation

Provides a single measurement (T2 distribution), can be used to

estimate porosity (�), pore size distribution (PSD), irreducible water

saturation (SWI) and Permeability (k) of formations

(1) (2)

1

��=

1

������

= ��

�

���

NMR Petrophysics

Estimating Estimating Estimating Estimating permeabilitypermeabilitypermeabilitypermeability (k)(k)(k)(k)

$%&' = (′�*(��+�,- �.)�

Estimating Estimating Estimating Estimating permeabilitypermeabilitypermeabilitypermeability (k)(k)(k)(k)

$ = (�*�

���

�

& �

���

= ����

$01' = (�*(� �� �)�

$%&' = (′�*(��+�,- �.)�

(3) From “NMR Logging - Principles ans Applications “

Surface Relaxivity �� homogeneous

throughout a formation

(3)

Is

?

23/10/2017

3

MICP• Laboratory Experiment to obtain the

Cappilary Pressure curve from rock samples, by injecting Mercury.

• The Cappilary Pressure curve can beconverted to a “pore throat size” distribution.

• This distribution can be used toestimate permeability and severalother types of petrophysical data.

• 21345 = (�*67 ��

• Can’t be used downhole.

• Destroys the sample.

67 = 29 :;<=

>�

MARSCHALL, D.et al: Method for correlating NMR relaxometry andmercury injection data. SCA Conference, 9511, p. 1-12, 1995.

• Found a simple way to correlate the PTD from MICP with the pseudo-PSD from NMR.

• 67 = ?� ��

201'@1345 = (�* � �� �

�

NMR-MICP Integration

23/10/2017

4

RIOS, E.H.; et al. NMR permeability estimators under differentrelaxation time selections: a laboratory study of cretaceousdiagenetic chalks. SPWLA, 55th Annual Logging Symposium, 2014

NMR-MICP Integration

• Different metrics to obtainthe representative value from T2 and Rt distributions.

• 201' = A�*�� ��

• 21345 = A�*67 ��

• Sized-Scaled estimators –Simple match between MICP (PTD) and NMR (PDS).

• <B, � =

'CDEF

GHDEF

• 2%IJ= A�* <B, �

�� �

�

Motivation

K core/log entries with:

• K porosities• K permeabilities

• K �� distributions• K 6L distributions

• 2K ∗ 3 pythagorian means• 2K ∗ 19 cutoffs (5% to 95%)

• K * 484 sHgs matches

• K NMR-MICP �N,�

• different pore shapes (?)

Then Calculate:• 6�

• Standard Error

Which is best?

And why?

21345 = (�*(67 �)�

2%IPDEF= (�*(�BQ �

�� �)�

201'@1345 = (�*(�� �� �)�

Different a,b,c:- Constant- Constrained- Unconstrained

201' = (′�*(�� �)�

23/10/2017

5

Goal

• Handle big datasets RCA and SCAL data or log.

• Automate calculations of all required parameters (means, cutoffs and ρ values) from NMR and MICP distributions.

• Enable fast evaluation of these permeability estimators.

• Facilitate the interpretation of results and comparison with the others models.

Speed-up the process for studying and evaluating these permeability estimators.

1- Sample Management• Samples’ Table for selecting subsets of data

• Interactive Cross-Plots

• Use the “Group” to segregate different formations, etc...

23/10/2017

6

1- Sample Management

2- Automation• NMIP imports all input data from Excel spreadsheets:

– NMR T2 distributions

– MICP Rt distributions

– Routine Core Analysis (porosity, absolute permeability, etc...)

– Any other petrophysical input.

• NMIP automatically tries to calculate:– All Pythagorian means (harmonic, geometric or “logarithmic”, arithmetic).

– Saturations cutoffs from 5% to 95%, with a 5% step

– sHg matches with all possible combinations

– NMR-MICP direct matching (Cross-Correlation)

• Create arbitrary cutoffs from NMR or MICP data.

• Run Custom Python Scripts.

• Possibility to edit the NMR-MICP match.

23/10/2017

7

3- Permeability ESTIMATION

4- Results

23/10/2017

8

4- Results$01' = (�*(1.0 ∗ ����7��)�

$01'@1345 = (�*(� ∗ ����7��)�

$%IJJET = (�*(�B,, �

∗ ����7��)�

2U = (�* 2%&' = (′�*(�N,�+�,)�

2%IPDEF= (�*(�BQ+�,

�N,�VW%)�201' = (�*(�� GH&'C

�N,�+�,)�

K estimation improved

NMR-MICP estimations

Classical k estimations

23/10/2017

9

Conclusions

• Success in accomplishing our goals.

• Positive feedback from pilot users.

• Project is open for ideas and suggestions.

• UFFLAR will register it as a free software.

• UFFLAR - UFF

• BG

• SCHLUMBERGER

• ANP

• RIO OIL AND GAS

Acknowledgments

23/10/2017

10

Thank you!

Email: pedroviannamesquita@gmail.com

NMIP characteristics• Written in python 2.7, using the default GUI API “Tkinter”

• Uses some of python’s free scientific modules:– Numpy – for fast numerical calculations.

– Scipy – collection of mathematical algorithms (interpolation, minimization)

– Matplotlib – for creating interactive plot figures.

• Imports and exports core data using excel files (convenient).– Modules: xlsxwriter, xlrd and xlwt

• Online license verification is required on startup (although, the software is completly free).

• Only works on Windows (for now).

23/10/2017

11

YW

NMR physics in 4 steps

RF Coil

RF Pulse

Polarization Excitation

B0

B0

Relaxation

Signal

Detection

Z[ from DT2 maps • Extraction of the surface

relaxivity Z[ from Diffusion T2

maps, by fitting a model to the logmean of a DT2 Map.

201' = A\�* �N,��� �

�

23/10/2017

12

Custom Interactive Plots• Set plot “configurations” to produce custom interactive figures

with available data• The configurations can also be stored, shared and reused.

Swap between samples

23/10/2017

13

Swap between samples

Swap between samples

23/10/2017

14